Established 2004

Ruddlesden geotechnical

Ruddlesden geotechnical provides ground investigation, geotechnical consultancy and contamination assessment services.

Based in Exeter, but covering the whole of the UK, albeit primarily concentrated in the South West, Ruddlesden geotechnical was formed in 2004.

Ruddlesden geotechnical works on behalf of a wide client base, including local, regional and national housing developers, housing associations, commercial developers, building contractors, structural and civil engineers, architects, building consultants, quantity surveyors, local authorities and private individuals.

Development projects range from single dwellings and extensions to large housing estates, multi-storey flats, offices, industrial units, roads, slopes, schools, hospitals and basements.

The services and projects listed on this web-site provide an indication of those undertaken by Ruddlesden geotechnical, but others are carried out. If your requirement is not readily identifiable on this web-site, please contact us as we may still be able to help you.

  • AGS
  • Constructionline
  • CSCS
  • SMAS
  • ECFC trust
  • Latest news

    25 Mar 2026

    BRE 365 Soakaway Testing

    Simon Ruddlesden was pleased to present at the AGS Annual Conference, to talk about BRE 365 soakaway testing, asking the question, though not necessarily providing the answer: Should we be carrying out BRE 365 soakaway testing in geologies where previous testing has shown soakaway/ infiltration drainage to be unsuitable? The BRE 365 soakaway test is widely accepted and requested as the field test that is to be carried out to assess the suitability of the ground for soakaway/ infiltration drainage. However, the test is not without danger, mainly due to working at height risks, and it is relatively wasteful of resources, including fuel and water. If previous testing results consistently and convincingly show that certain geologies are unsuitable for soakaway/ infiltration drainage, should a relatively unsafe and not particularly sustainable test be carried out? Using data from over 5,000 tests on more than 1,200 sites investigated by Ruddlesden geotechnical over the last 20 years, mainly in the South West, there is a clear and understandable correlation between unsuccessful tests and the underlying geology, where the underlying geology comprises predominantly lower permeability mudstones and clays, notably the Mercia Mudstone Group, Lias Group and Oxford Clay Formation, although there are a number of anomalies, which can usually be explained by a closer inspection of the local geology, including superficial deposits. More data and research will be required if regulators and designers are to accept that no testing is required in certain geologies. The presentation sparked an interesting discussion afterwards, and it is hoped that it will have inspired others to share their data and/ or offer technical support, to ultimately produce a map that provides confidence to regulators and designers that BRE 365 testing is not required in certain geologies. Please contact us directly if you would like to discuss this further.

    BRE 365 Soakaway Testing
    BRE 365 Soakaway Testing
  • Recent projects

    CPT Testing Used to Supplement Borehole Data

    Following an initial phase of geotechnical investigation, comprising cable percussive boreholes, cone penetration (CPT) testing was undertaken to obtain a greater resolution of data, to confirm the ground and groundwater conditions beneath the site. The testing caused minimal site disturbance, which was critical, as the site investigation works were being undertaken within the confines of a residential care home. The testing was also rapid, which allowed many locations to be undertaken within a day, meaning that any inconvenience caused to the residents was limited to a single day. Ruddlesden geotechnical commissioned an international contractor to undertake the testing and provided on site supervision and interpretation of the data, which was ultimately used to inform a foundation options appraisal.

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  • Recent projects

    Dynamic Sampling was Preferred Method of Investigation in Devon

    Dynamic sampling (windowless sample boreholes) was utilised in a scheme of works for the proposed stabilisation and reinstatement of a quay wall. This was the preferred method for the initial geotechnical investigation at this site, as they allowed representative samples of the near surface soils to be obtained, facilitated Standard Penetration Tests (SPTs) and were able to be progressed down to depths of 6m-8m to determine the presence of engineering rock-head, all whilst keeping site disturbance and the areal extent of the site works to a minimum, allowing the adjacent car park to be in continued use without the need for closure. On completion of the ground investigation, the boreholes were either installed with monitoring wells, to facilitate long-term groundwater and/ or ground gas monitoring, or backfilled with natural arisings prior to reinstatement.

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